1. Field of the Invention
This invention relates to a means for securing the lower end of a wind turbine tower to a foundation and more particularly to a means for securing the lower end of a wind turbine tower to a foundation wherein the wind turbine tower is comprised of a plurality of elongated hollow pole sections secured together in an end-to-end relationship with each of the pole sections comprising a plurality of longitudinally extending peripheral sections joined together with each of the peripheral sections being bent along a plurality of longitudinally extending break lines to define a plurality of angled wall sections extending between inwardly extending edge portions. Although the preferred construction of the pole sections is that described above, the wall sections of the peripheral sections could be curved rather than angled. Further, the edge portions of the peripheral sections could extend outwardly, or be in an overlapping or abutting relationship.
2. Description of the Related Art
Wind turbines are becoming more popular in the production of electrical energy. A wind turbine normally comprises a rotor-driven generator mounted atop a tower which may reach heights of 70 meters or more. Normally, the lower end of the tower is bolted or anchored to a foundation embedded in the ground.
In assignee's U.S. Pat. Nos. 6,278,198; 6,505,785; and 6,522,025, a wind turbine is shown to be mounted on the upper end of a tubular tower comprised of tubular pole sections secured to one another in an end-to-end fashion. In assignee's co-pending application Ser. No. 10/797,778 filed Mar. 10, 2004, entitled “HOLLOW STRUCTURAL MEMBER”, the wind turbine tower is comprised of a plurality of elongated hollow pole sections secured together in an end-to-end relationship with each of the hollow pole sections comprising a plurality of longitudinally extending peripheral sections joined together. Each of the peripheral sections is bent along a plurality of longitudinally extending break lines to define a plurality of angled wall sections extending between inwardly extending edge portions. The edge portions of the peripheral sections are bolted together to form a hollow pole section.
The fact that the hollow structural member (wind turbine tower) of the co-pending application is not perfectly cylindrical or tubular in shape makes it somewhat difficult to anchor or bolt the lowermost pole section to the foundation. A further complicating factor in securing the tower of the co-pending application to a foundation is the fact that the inwardly extending edge portions of the peripheral sections make it difficult to bolt or anchor the tower to the foundation.